1. Field of the Invention
The present invention relates to a method and apparatus for inverting articles and, more particularly, to such apparatus which comprises a pair of hinged plates with vacuum control means for transferring a set of inverted articles from one plate to another as the plates are brought together.
2. Description of the Prior Art
Many systems utilize components which have a preferred orientation for their intended use. During the manufacture of such components, it is often necessary to correctly orient them before testing their integrity. Prior art inversion systems utilized suction cups and pivotal members to reverse articles. Descriptions of such systems may be found in U.S. Pat. No. 3,522,582 issued to K. E. Hanft on Jan. 5, 1971, and U.S. Pat. No. 4,498,840 issued to M. Orii on Feb. 12, 1985.
In some systems, most notably integrated circuit and lightwave systems, many components are extremely small and are not well-suited for use with the systems disclosed by Hanft and Orii. In lightwave systems, for example, the transmitting and detecting components may become inverted during handling and must be righted before testing. Turning of individual components by hand may be accomplished by an operator on the assembly line. These components, however, are very small in size (on the order of 10 mils.times.10 mils) and it is extremely time-consuming for inverted chips to be turned by hand using a tool such as a micromanipulator. An alternative system previously proposed pushes the components off of a ledge where approximately 60% of the components will land right side up after falling a predetermined distance. Additional attempts at reorientation are then used to flip over those chips that did not invert the first time. Thus, to achieve 100% inversion, this push-off technique must be repeated a number of times, where the number of tries required will vary from time to time. Obviously, this is not a preferred technique for inverting fragile components.
Thus, a need remains for an arrangement for inverting articles, especially fragile components, which is relatively fast and capable of inverting all of the articles without requiring human intervention.